Consider a simple economy where the basket of goods used to calculate the CPI contains two items: shampoo and soap. The basket consists of 1 bottle of shampoo and 2 bars of soap. The prices are shown in the table.

\begin{tabular}{|l|l|l|}
\hline Year & Price of a Bottle of Shampoo & Price of a Bar of Soap \\
\hline Year 1 & \[tex]$6.50 & \$[/tex]1.25 \\
\hline Year 2 & \[tex]$6.60 & \$[/tex]1.30 \\
\hline
\end{tabular}

Type the correct answer in the box. Round your answer to two decimal places, if necessary.

The CPI for year 2 is [tex]$\square$[/tex].



Answer :

To determine the Consumer Price Index (CPI) for Year 2, we need to follow a series of steps. The CPI measures the average change in prices over time that consumers pay for a basket of goods and services.

1. Identify the Basket of Goods:
- The basket consists of 1 bottle of shampoo and 2 bars of soap.

2. Determine the Prices for Year 1:
- Price of 1 bottle of shampoo: [tex]$6.50 - Price of 1 bar of soap: $[/tex]1.25

3. Calculate the Total Cost of the Basket in Year 1:
- [tex]\( \text{Cost}_{\text{Year 1}} = (\text{Price of 1 bottle of shampoo} \times \text{Quantity of shampoo}) + (\text{Price of 1 bar of soap} \times \text{Quantity of soap}) \)[/tex]
- [tex]\( \text{Cost}_{\text{Year 1}} = (6.50 \times 1) + (1.25 \times 2) \)[/tex]
- [tex]\( \text{Cost}_{\text{Year 1}} = 6.50 + 2.50 = 9.00 \)[/tex]

4. Determine the Prices for Year 2:
- Price of 1 bottle of shampoo: [tex]$6.60 - Price of 1 bar of soap: $[/tex]1.30

5. Calculate the Total Cost of the Basket in Year 2:
- [tex]\( \text{Cost}_{\text{Year 2}} = (\text{Price of 1 bottle of shampoo} \times \text{Quantity of shampoo}) + (\text{Price of 1 bar of soap} \times \text{Quantity of soap}) \)[/tex]
- [tex]\( \text{Cost}_{\text{Year 2}} = (6.60 \times 1) + (1.30 \times 2) \)[/tex]
- [tex]\( \text{Cost}_{\text{Year 2}} = 6.60 + 2.60 = 9.20 \)[/tex]

6. Calculate the CPI for Year 2:
- The CPI for Year 1 is considered the base year and is set to 100.
- [tex]\( \text{CPI}_{\text{Year 2}} = \left( \frac{\text{Cost}_{\text{Year 2}}}{\text{Cost}_{\text{Year 1}}} \right) \times 100 \)[/tex]
- [tex]\( \text{CPI}_{\text{Year 2}} = \left( \frac{9.20}{9.00} \right) \times 100 \)[/tex]
- [tex]\( \text{CPI}_{\text{Year 2}} = 1.0222 \times 100 \)[/tex]
- [tex]\( \text{CPI}_{\text{Year 2}} = 102.22 \)[/tex]

Therefore, the CPI for Year 2 is 102.22.